This involves a method for electrically powering an ignition spark plug up to an electric voltage ensuring the generation of a branched ignition spark in particular of an internal combustion engine.
Also involved is a device for powering such a spark plug, this device comprising means for powering the spark plug with electrical energy up to a voltage ensuring the generation of a branched ignition spark.
In order to have better control over igniting the flammable mixture in an internal combustion engine, it is known to be preferable to use an electric spark of considerable size. Specifically, the larger the spark, the greater the probability of there being a meeting between the hot electric arc and the cloud of fuel and the more efficient the ignition. For a conventional ignition spark plug, the size of the spark (of the order of one mm cubed) is limited by the distance between two electrodes of the spark plug.
In order to increase the size of the spark of an ignition spark plug, it has already been proposed:                in U.S. Pat. No. 5,623,179, to increase the distance between the electrodes of the spark plug; however such a solution requires a particularly high powering voltage,        which is directly proportional to the distance between the electrodes,        in EP-A-1202411 or EP-A-1526618, to use the electric arc which slides over the insulation of the spark plug, which makes it possible to lengthen the spark without increasing the electric voltage by too much; however, in such a solution, the lengthening of the spark remains relatively short and the insulating surface touched by the hot arc quickly degrades;        in FR-A-2886776 or FR-A-2878086, to form a multifilament radio frequency spark developing from a single pointed electrode; this makes it possible to increase notably the length of the spark, but in the known method of this solution, the number of filaments formed simultaneously is limited (2-3 at most).        